Preparation and Spectral Properties of MgAl2O4: Tb3+ Phosphor

A series of Tb3+ doped cubic MgAl2O4 green phosphors were synthesized via hydrothermal method followed by a post-annealing process. The variation regularity of phase structure, morphology, particle size and concentration quenching mechanism were investigated. The results showed that the crystal structure of matrix materials was not affected when Tb3+ ions were introduced. In addition, the micrometer-sized rods and excellent dispersion of the particles were obtained by adding urea. Under excitation at 377 nm, the phosphors exhibited the characteristic of Tb3+ emissions with the peaks located at 488 nm (5D4 → 7F6), 544 nm (5D4 → 7F5) and 588 nm (5D4 → 7F4), respectively. Moreover, based on optical analysis, it can be inferred that electric dipole-dipole (d-d) interaction plays an important role in concentration quenching process of Tb3+ ions. The green light emitting phosphor MgAl2O4: Tb3+ can be realized by adjusting the concentrations of Tb3+, and the optimum concentration of Tb3+ ions in MgAl2O4 was found to be 0.02. Finally, the average fluorescence decay lifetime and the CIE chromaticity coordinates of Mg0.98Al2O4: 0.02Tb3+ phosphor were calculated to be 1.2005 ms and (0.3197 0.4109), respectively. The above results suggest that the developed phosphor could have potential to be used as a single-phase green emission phosphor for near-ultraviolet light-emitting diode (NUV-LED) applications.